This application relates to an electrode puck for use in cathodic arc coating wherein a continuous groove is formed to aid in the manipulation of the movement of the electric arc, and eliminate a tendency to stall in a pore in the puck.
Cathodic arc coating systems are known, and typically include one electrode or cathode formed of coating material. Typically, the puck is the cathode. Electrical connections are made to both the cathode, and typically a chamber surrounding the cathode. The chamber is typically connected to be an anode.
An electrical arc travels around the cathode which causes the evaporation of the cathode material as a vapor cloud at the spots where the arc touches the puck. A magnetic force is induced around the cathode, and this magnetic force aids in steering the arc around the perimeter of the puck, thus, the vapor cloud is formed around the circumference of the surface of the cathode. Parts to be coated are located in the path or throw of this cloud. The magnetic force is rotated to cause the arc to move continuously around the cathode. In this manner, a cloud is formed uniformly about a central axis of the cathode puck, and the parts are evenly coated.
However, in practice, there is one concern wherein the puck may have a porosity that causes the arc to stall within a pore and the magnetic field which helps steer the arc cannot overcome the geometrical constraints encountered by such porosity. That is, the arc will not continue to rotate uniformly about the puck and thus the vapor cloud will not be formed uniformly within the chamber. When this occurs, the coating deposited onto the parts is not uniform.